Find the sum S of the infinite series Σk=1∞ 18·(1/2)ᵏ.
Sequences & series worksheet with answers
1.Easy
a = 18r = 1/2k₀ = 1
S =
2.Easy
Find the sum S of the infinite series Σk=1∞ 24·(2/3)ᵏ.
a = 24r = 2/3k₀ = 1
S =
3.Medium
Find the sum S = Σk=1∞ 1/(k(k + 4)).
ak = 1/(k(k + 4))
S =
4.Medium
Exactly one of the four series diverges. Click it.
A: Σ (−1)ᵏ/kB: Σ 3ᵏ/k³C: Σ 3/k³D: Σ 10ᵏ/k!
- 1A: Σ (−1)ᵏ/k
- 2B: Σ 3ᵏ/k³
- 3C: Σ 3/k³
- 4D: Σ 10ᵏ/k!
5.Hard
f(x) = ln(1 + x) is approximated by its Maclaurin polynomial of degree 3 at x = 0.3. Use the Lagrange error bound M·|x|ⁿ⁺¹/(n + 1)! with M = 3! = 6 to find the largest possible error |R₃|.
f(x) = ln(1 + x)n = 3x = 0.3M = 6
|R₃| =
6.Hard
Recognise the series and find its sum: S = Σk=1∞ (−1)k+1·0.2ᵏ/k.
ak = (−1)k+1·0.2ᵏ/k
S =
Answer key
- 1. S = 18
- 2. S = 48
- 3. S = 0.5208
- 4. B: Σ 3ᵏ/k³
- 5. |R₃| = 0.002025
- 6. S = 0.1823
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